Antarctic Blue Whale and Krill Voyage 2019

Blue whales and krill

Antarctic blue whales are not only the biggest animals on the planet, they’re the largest that have ever existed. Adults reach more than 30 metres in length, 100 tonnes in weight, and live for more than 80 years. The blue whale is also arguably one of the noisiest animals, regularly making intense low-frequency calls that travel underwater for hundreds of kilometres.

Hunted to near extinction until the 1970s, the population of Antarctic blue whales was reduced to a few hundred individuals. Today, while their population is recovering, blue whales remain rare and endangered. Where they migrate to breed is currently unknown.

Antarctic blue whales almost exclusively eat krill, and in vast amounts. In one day, an adult blue whale can eat up to 4 million krill, more than three tonnes. To do this, they must feed in areas where they can find high krill concentrations. They spend summer in the krill-rich waters around the Antarctic ice edge. More study needs to be done to understand how these enormous krill swarms are distributed in the Southern Ocean.

Antarctic krill are one of the most abundant and successful animal species on Earth. Scientists estimate there are about 500 million tonnes of Antarctic krill in the Southern Ocean. The biomass of this one species may be the largest of any multi-cellular animal species on the planet.

Antarctic Blue Whale and Krill Voyage 2019

Do krill swarms affect the distribution and behaviour of whales? How does the mix of predators, prey and their poo affect productivity in the Southern Ocean?

These are just some of the questions a team of 28 krill, whale and biogeochemistry experts want to answer during an ambitious 49 day voyage aboard the CSIRO research vessel Investigator this summer to East Antarctica and the Ross Sea region.

This research is part of the Australian Antarctic Program, supported by a grant of sea time on RV Investigator from the CSIRO Marine National Facility.

The voyage is called ENRICH, standing for ‘Euphausids and Nutrient Recycling In Cetacean Hotspots’ (note: euphausids are krill, cetaceans are whales).

Scientists hope to get an intimate glimpse into the daily lives of both blue whales and krill, using a range of technologies like underwater listening devices (sonobuoys), multibeam echosounders, and even drones to photograph whales and collect their blow and faeces.

The voyage departs Hobart on 19 January 2019 and returns on 6 March 2019.

Team members

Dr Mike Double - Chief Scientist

As a zoologist and geneticist, I lead the Australian Marine Mammal Centre (AMMC). We conduct scientific research that contributes to the conservation and management of marine mammals around Australia, through the Pacific and in Antarctic waters. Our Centre’s research leads the way in informing the world about all whale species. Our non-lethal scientific research shows that you don’t need to kill whales to study them. As the Chief Scientist on this voyage, our aim is to explore the interdependent roles of whales and krill in the Antarctic ecosystem, to inform the management of expanding krill fisheries. This is the most comprehensive scientific voyage ever undertaken on Antarctic blue whales and their prey, Antarctic krill.

Dr Elanor Bell - Deputy Chief Scientist / Biogeochemist

I am a microbial ecologist by training but have turned my hand from whale food to the whales themselves. On this voyage we’ll be doing the first in-field experiments to test the theory that whales fertilise the ocean with iron, after eating iron-rich krill and excreting the metal in their faeces. We’ll sample water in areas with whales and krill, whales only, krill only, and neither species. The sampling will reveal where the iron goes, how fast it sinks, and whether primary production increases over time.

Dr Karen Westwood - Voyage Project Manager / Biogeochemist

My research focusses on single celled organisms in the Southern Ocean called marine microbes (bacteria, phytoplankton, protozoa). These organisms are important for two main reasons: they form the base of the Antarctic food web, and they drive the biological pump in the Southern Ocean where up to 12 percent of anthropogenic CO2 emissions are absorbed. I’ll be examining whether whales stimulate primary and bacterial production through their iron-rich faeces (iron normally limits growth of marine microbes), by deploying a marker buoy to drift with a whale “poo-patch”, and by sampling in regions where whales and krill are present or absent.

Dr Brian Miller - Whale Acoustician

To find the blue whales in the vast Southern Ocean, we’ll use small underwater listening devices called sonobuoys to locate and track them. These can detect the whale’s low frequency calls from up to 1000 kilometres away. Real-time acoustic tracking provides a reliable and efficient way to find extremely rare Antarctic blue whales. Sonobuoy surveys may also provide an important link between visually observed behaviour and acoustic behaviour.

My main research interests focus on marine mammal behaviour and behavioural ecology, bioacoustics and spatial risk assessments. On this voyage, I will be leading the drone operations to obtain measurements and photo-identification of the whales. We also hope to obtain blow samples from the whales to collect mucus when the whale exhales as a way of monitoring the health of the whale, and will also attempt to sample surface water for whale faeces.

Dr So Kawaguchi - Krill Ecologist

Using the RV Investigator’s multibeam echosounders, we want to develop the first 3D models of the shape, size, and density of krill swarms underwater, near whales and elsewhere. Krill swarms can be deep or shallow, dense or diffuse, but little is known about the different swarm types and whether some are more attractive to whales than others. We’ll also do some targeted krill trawls to gather information on the species, biomass and size.